Jaw and finger movements during visual and auditory motor tracking tasks
By S.G. Adams, G. Gauthier, J.L. Vercher, and M. Jog
The present study examined jaw and finger motor performance during visual and auditory motor tracking tasks in 12 normal subjects. The effects of delayed visual and auditory feedback on jaw and finger tracking performance were also examined. During visual sinusoidal tracking the jaw showed greater average tracking error than the finger. In contrast, during the auditory sinusoidal tracking the finger showed greater tracking error than the jaw. In addition, the auditory step tracking task was associated with significantly longer response times (100-120 ms) for both the jaw and finger than the visual step tracking task. Static visual tracking was also found to be associated with significantly greater tracking error than static auditory tracking. These tracking results suggest that there are important differences between the oral-auditory and the manual-visual sensorimotor systems. The introduction of auditory and visual delays at 250 and 500 ms. were associated with significant increases in the error, gain and the phase lag of both the jaw and finger movements. Overall, the sensory delay results suggest that auditory and visual delays had fairly similar effects on the oral and manual movement systems.